Israeli Defense Minister Ehud Barak ordered the military to prepare to invade Gaza, and told Israeli lawmakers that under certain circumstances, Israel would "even take down Hamas."

Barak spoke at a closed parliamentary meeting whose discussions routinely are leaked to the media. It was the first time a senior Israeli official hinted so strongly that Israel was prepared to overthrow Hamas if the Palestinians didn't do it themselves.

Israel, which is negotiating a peace deal with moderate Palestinians based in the West Bank, has made it clear it has no intention of implementing any accord until Hamas is removed from power in Gaza.

The Islamic militants, who are committed to Israel's destruction, violently wrested control of the tiny seaside territory in June from security forces loyal to moderate Palestinian President Mahmoud Abbas, Israel's partner in peace negotiations.

In a related development, a close ally of Israeli Prime Minister Ehud Olmert's said Hamas' days were numbered.

"I believe the combination of (Israeli) steps against Hamas in Gaza will bring an end to the Hamas regime in Gaza," Vice Premier Haim Ramon said. It might take a few months, but "the Hamas regime in Gaza will not last," Ramon told reporters in Jerusalem.

Sleeping in safehousesGaza Prime Minister Ismail Haniyeh and other top Hamas officials haven't been seen in public for days. They were sleeping in safehouses and avoiding crowds, and staying out of cars for fear Israel would strike the vehicles from the air, the officials said. They also switched off their cell phones, afraid they could be tracked, they added.

"We are taking all the precautions. We take the Israeli threats seriously," said Hamas spokesman Fawzi Barhoum.

For months, Israel has been carrying out brief ground incursions and pinpoint airstrikes inside Gaza in efforts to halt ongoing rocket fire on southern Israel. Although Israel says it has killed some 200 militants in recent months, the rocket fire has persisted. In addition to the rocket attacks, the group claimed responsibility for a suicide bombing last week that killed an elderly Israeli woman.

Pressure has been building on Olmert to take tougher action after an 8-year-old Israeli boy from the southern town of Sderot lost a leg in a Palestinian rocket attack Saturday. Protesters from Sderot blocked traffic on a major Tel Aviv highway, demanding that Olmert resign and sounding air raid sirens.

Barak told parliament's Foreign Affairs and Defense Committee that Israel's long-term plan was to weaken Hamas and "under certain circumstances even taken down Hamas," a meeting participant said.

"I don't see the Palestinians giving Gaza back to Fatah. Outside developments might bring this about," the participant quoted Barak as saying. He spoke on condition of anonymity because the meeting was confidential.

Speaking to reporters after the meeting, Barak said he ordered the military to prepare for a broad operation in Gaza, but emphasized the offensive would not take place immediately. In the meantime, he said, the army "will operate in every way" to halt the rocket fire on southern Israel.

"There are military operations every day and night and they will be broadened further," he said. "A broad operation in Gaza is closer today, but won't take place in a matter of days."

'Intensifying the assassinations' likelyAn Israeli defense official said Israel's strategy would include "intensifying the assassinations" on Gaza militants. He declined to say whether Hamas leaders would be targeted. He spoke on condition of anonymity because he was not authorized to discuss policy with the media.

Up to now, Israeli military strikes have been aimed at rocket squads and militant leaders, while sparing political leaders. In 2004, however, Israel killed the founder of Hamas and his successor in two airstrikes four weeks apart.

"We need to topple the Hamas regime," Tzachi Hanegbi, chairman of the Foreign Affairs and Defense Committee, told Israel Radio ahead of Barak's briefing. "We need to assassinate its leaders without any artificial differentiation between those who wear explosive vests and those who wear diplomatic vests."

Sami Abu Zuhri, a Hamas spokesman, told a Hamas Web site that assassinating the group's leaders would be a "dangerous escalation" and warned of an "unprecedented" response.

He also said Israel would not succeed in bringing down Hamas.

"These comments by Barak and Ramon confirm that the aim of the current aggression on Gaza isn't about security, it is political, and it aims to try destroy Hamas. But it's a failed war, and it will fail," he said.

As Israel battles Hamas in Gaza, it has been carrying on peace talks with Abbas' government.

Ramon on Monday appeared to scale back expectations for reaching a peace agreement with the Palestinians this year, saying instead that Israel hoped the two sides would reach a "declaration of principles."

Ramon said the target was not a full agreement, but a document detailed enough to set out a program for establishing a Palestinian state over two to three years.

At a U.S.-sponsored peace conference in November, the two sides formally resumed negotiations and pledged to reach a "a peace treaty resolving all outstanding issues" by the end of 2008.

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